This application claims the priority of 198 47 552.7, filed Oct. 15, 1998, the disclosure of which is expressly incorporated by reference herein.
The present invention relates to a system for punching and bundling metal sheets having a die for punching the metal sheets, a die plate cooperating with the die, a receiving shaft for receiving and stacking the punched metal sheets, a separating device for separating the metal sheets stacked in the receiving shaft. Furthermore, the present invention relates to a process for punching and bundling metal sheets in which metal sheets are punched by means of a die and a die plate cooperating with the die, onto a metal sheet stack.
A known type of punching and bundling system is described in DE 31 47 034 A1. A certain number of metal sheets situated in the receiving shaft are displaced to the side as metal sheets bundles by way of a cross slide, while the metal sheets situated above this metal sheet bundle are held in the receiving shaft. The metal sheets which were pushed to the side can then in each case be transported and processed as metal sheet bundles. The entire operation takes place during the punching of the metal sheets.
It is a disadvantage of this system and of the associated process that all components must have very precise tolerances and their manufacturing is therefore very expensive. The process itself is very complicated, and extremely cumbersome resetting operations are required for producing metal sheet bundles of different heights. In addition, metal sheet bundles of continuously precise heights cannot be produced with this system.
DE 28 39 928 A1 describes a system for conveying, stacking and bundling, corresponding to the correct punching pattern, of metal sheets of electric machines. A welding device is mounted below the die plate for continuously successively welding together the metal sheets and discharging them from the press as a strip. With this system, metal sheet bundles of a predetermined length can also be produced. The precision required for this purpose cannot, however, be achieved with the construction of the disclosed welding device.
A similar system is described in EP 0 343 661 A1. There, the metal sheet bundles are welded directly in the die plate in that a welding spot is set at each stroke of the die. The welding device cannot operate continuously, however, whereby the welds only have a very limited durability. Another disadvantage of this known welding device is that a portion of the laser lens system of the welding device is mounted inside the tool and must remain on it, or must be newly mounted and aligned during each tool change at high expenditures.
DE 26 05 983 C3 and DE 26 30 867 C2 describe additional systems for stacking and bundling punched parts, in which case, by way of a mandrel, a slide, a cylinder/piston unit as well as a pawl, intermediate stacks are formed of the punched plates. These systems have a disadvantage in that, during the resetting to other metal sheets, the mandrels must be exchanged in a cumbersome manner.
With respect to additional prior art concerning systems for punching and bundling metal sheets, reference is also made to DE 20 65 645 A1; DE 23 39 322 A1; DE 26 19 127 A1; and DE 27 06 274 A1.